Extent of coronary and myocardial disease and benefit from surgical revascularization in ischemic LV dysfunction [Corrected]

Current indications and surgical strategies for myocardial revascularization in patients with left ventricular dysfunction: a scoping review

BACKGROUND

Ischemic cardiomyopathy (ICM) accounts for more than 60% of congestive heart failure cases and is associated with high morbidity and mortality rates. Myocardial revascularization in patients with left ventricular dysfunction (LVD) and a left ventricular ejection fraction (LVEF) ≤35% aims to improve survival and quality of life and reduce complications associated with heart failure and coronary artery disease. The majority of randomized clinical trials have consistently excluded those patients, resulting in evidence primarily derived from observational studies.

MAIN BODY

We performed a scoping review using the Arksey and O'Malley methodology in five stages: 1) formulating the research question; 2) locating relevant studies; 3) choosing studies; 4) organizing and extracting data; and 5) compiling, summarizing, and presenting the findings. This literature review covers primary studies and systematic reviews focusing on surgical revascularization strategies in adult patients with ischemic left ventricular dysfunction (LVD) and a left ventricular ejection fraction (LVEF) of 35% or lower. Through an extensive search of Medline and the Cochrane Library, a systematic review was conducted to address three questions regarding myocardial revascularization in these patients. These questions outline the current knowledge on this topic, current surgical strategies (off-pump vs. on-pump), and graft options (including hybrid techniques) utilized for revascularization. Three independent reviewers (MAE, DP, and AM) applied the inclusion criteria to all the included studies, obtaining the full texts of the most relevant studies. The reviewers subsequently assessed these articles to make the final decision on their inclusion in the review. Out of the initial 385 references, 156 were chosen for a detailed review. After examining the full articles were examined, 134 were found suitable for scoping review.

CONCLUSION

The literature notes the scarcity of surgical revascularization in LVD patients in randomized studies, with observational data supporting coronary revascularization's benefits. ONCABG is recommended for multivessel disease in LVD with LVEF < 35%, while OPCAB is proposed for older, high-risk patients. Strategies like internal thoracic artery skeletonization harvesting and postoperative glycemic control mitigate risks with BITA in uncontrolled diabetes. Total arterial revascularization maximizes long-term survival, and hybrid revascularization offers advantages like shorter hospital stays and reduced costs for significant LAD lesions.

Medical Decision-Making and Revascularization in Ischemic Cardiomyopathy

Ischemic cardiomyopathy (ICM) is the most common underlying etiology of heart failure in the United States and is a significant contributor to deaths due to cardiovascular disease worldwide. The diagnosis and management of ICM has advanced significantly over the past few decades, and the evidence for medical therapy in ICM is both compelling and robust. This contrasts with evidence for coronary revascularization, which is more controversial and favors surgical approaches. This review will examine landmark clinical trial results in detail as well as provide a comprehensive overview of the current epidemiology, diagnostic approaches, and management strategies of ICM.

A treatment algorithm for ischemic cardiomyopathy

Treatment of ischemic cardiomyopathy has been the focus of increased attention by cardiologists due to recent evidence of an important outcome study comparing percutaneous coronary intervention (PCI) plus optimal medical treatment vs optimal medical treatment alone, concluding for the futility of myocardial revascularization by PCI. A relatively older trial of coronary artery bypass grafting (CABG) in the same condition, on the other hand, had concluded for some prognostic improvement at a long-term follow-up. This short manuscript addresses how to triage such patients, frequently encountered in medical practice and considering clinical presentation, imaging results, and surgical risk, to provide practical guidance to treatment.

[Amélioration précoce de la fraction d'éjection chez les patients ayant une fraction d'éjection réduite après un pontage coronarien]

BACKGROUND

Despite advancements in surgical technique, myocardial shield, and postoperative care, Coronary artery bypass grafting (CABG) among patients with reduced ejection fraction (EF) remains a surgical challenge due to their greater postoperative morbidity and mortality. This study aims to determine the early outcome of patients with reduced LVEF undergoing CABG and the improvement in the ejection fraction after revascularization.

METHODS

A total of 62 patients with impaired Left Ventricular (LV) systolic function (LVEF = 35-40 %) who underwent isolated On-pump CABG at the Department of Cardiothoracic Surgery in Assiut University Hospitals and who had met the listed inclusion and exclusion criteria were eligible for the study. Different variables (preoperative, intraoperative, and postoperative) were collected, studied, and compared.

RESULTS

The mean age of the patients was 57.81 ± 7.57 years, 66.1 % were male and 33.9 % were female. 44 (71.0%) patients were administered antegrade cardioplegia, whereas 18 (29.0%) patients were administered antegrade plus retrograde cardioplegia. Mean LVEF increased significantly from 37.97 ± 1.38% before surgery to 51.87 ± 3.54% after surgery (P ˂ 0.05). Post-operative low cardiac output syndrome occurred in 37 (59.7 %) of patients, pulmonary complications in 15 (24.2%), neurological complications in 10 (16.1%), sternal wound infection in 9 (14.5%), atrial fibrillation in 5 (8.1%) and acute kidney injury in 5 (8.1 %) of patients. In-hospital mortality was 16.1% (10 patients).

CONCLUSION

Based on the findings, CABG in patients with reduced preoperative LVEF improves the postoperative LVEF and NYHA functional class.

The Evolving Paradigm of Revascularization in Ischemic Cardiomyopathy: from Recovery of Systolic Function to Protection Against Future Ischemic Events

PURPOSE OF REVIEW

We aim to reevaluate how the assessment of myocardial viability can guide optimal treatment strategies for patients with ischemic cardiomyopathy (ICM) based on a more contemporary understanding of the mechanism of benefit of revascularization.

RECENT FINDINGS

The assessment of viability in left ventricular (LV) segments with diminished contraction has been proposed as key to predict the benefit of revascularization and, therefore, as a requisite for the selection of patients to undergo this form of treatment. However, data from prospective trials have diverged from earlier retrospective studies. Traditional binary viability assessment may oversimplify ICM's complexity and the nuances of revascularization benefits. A conceptual shift from the traditional paradigm centered on the assessment of viability as a dichotomous variable to a more comprehensive approach encompassing a thorough understanding of ICM's complex pathophysiology and the salutary effect of revascularization in the prevention of myocardial infarction and ventricular arrhythmias is required.

Heterogeneous treatment effects of coronary artery bypass grafting in ischemic cardiomyopathy: A machine learning causal forest analysis

OBJECTIVES

We aim to evaluate the heterogeneous treatment effects of coronary artery bypass grafting in patients with ischemic cardiomyopathy and to identify a group of patients to have greater benefits from coronary artery bypass grafting compared with medical therapy alone.

METHODS

Machine learning causal forest modeling was performed to identify the heterogeneous treatment effects of coronary artery bypass grafting in patients with ischemic cardiomyopathy from the Surgical Treatment for Ischemic Heart Failure trial. The risks of death from any cause and death from cardiovascular causes between coronary artery bypass grafting and medical therapy alone were assessed in the identified subgroups.

RESULTS

Among 1212 patients enrolled in the Surgical Treatment for Ischemic Heart Failure trial, left ventricular end-systolic volume index, serum creatinine, and age were identified by the machine learning algorithm to distinguish patients with heterogeneous treatment effects. Among patients with left ventricular end-systolic volume index greater than 84 mL/m2 and age 60.27 years or less, coronary artery bypass grafting was associated with a significantly lower risk of death from any cause (adjusted hazard ratio, 0.61; 95% CI, 0.45-0.84) and death from cardiovascular causes (adjusted hazard ratio, 0.63; 95% CI, 0.45-0.89). By contrast, the survival benefits of coronary artery bypass grafting no longer exist in patients with left ventricular end-systolic volume index 84 mL/m2 or less and serum creatinine 1.04 mg/dL or less, or patients with left ventricular end-systolic volume index greater than 84 mL/m2 and age more than 60.27 years.

CONCLUSIONS

The current post hoc analysis of the Surgical Treatment for Ischemic Heart Failure trial identified heterogeneous treatment effects of coronary artery bypass grafting in patients with ischemic cardiomyopathy. Younger patients with severe left ventricular enlargement were more likely to derive greater survival benefits from coronary artery bypass grafting.

Impact of complete revascularization in coronary artery bypass grafting for ischemic cardiomyopathy

Objective

In patients with ischemic cardiomyopathy, coronary artery bypass grafting ensures better survival than medical therapy. However, the long-term clinical impact of complete revascularization remains unclear. This observational study aimed to evaluate the effects of complete revascularization on long-term survival and left ventricular functional recovery in patients with ischemic cardiomyopathy undergoing coronary artery bypass grafting.

Methods

We retrospectively reviewed outcomes of 498 patients with ischemic cardiomyopathy who underwent complete (n = 386) or incomplete (n = 112) myocardial revascularization between 1993 and 2015. The baseline characteristics were adjusted using inverse probability of treatment weighting to reduce the impact of treatment bias and potential confounding. The mean follow-up duration was 77.2 ± 42.8 months in survivors.

Results

The overall 5-year survival rate (complete revascularization, 72.5% vs incomplete revascularization, 57.9%, P = .03) and freedom from all-cause death and/or readmission due to heart failure (54.5% vs 40.1%, P = .007) were significantly greater in patients with complete revascularization than those with incomplete revascularization. After adjustments using inverse probability of treatment weighting, the complete revascularization group demonstrated a lower risk of all-cause death (hazard ratio, 0.61; 95% confidence interval, 0.43-0.86; P = .005) and composite adverse events (hazard ratio, 0.59; 95% confidence interval, 0.44-0.79; P < .001) and a greater improvement in the left ventricular ejection fraction 1-year postoperatively (absolute change: 11.0 ± 11.9% vs 8.3 ± 11.4%, interaction effect P = .05) than the incomplete revascularization group.

Conclusions

In patients with ischemic cardiomyopathy undergoing coronary artery bypass grafting, complete revascularization was associated with better long-term outcomes and greater left ventricular functional recovery and should be encouraged whenever possible.

What is the role of coronary revascularization to recover the contractility of the dysfunctional heart?

Coronary artery disease is the predominant aetiology of heart failure and left ventricular dysfunction in industrialized countries. The pathophysiological substrate of hibernating myocardium constitutes the conceptual target of coronary revascularization by coronary artery bypass graft (CABG) or coronary angioplasty or percutaneous coronary intervention (PCI). Studies, mainly observational, conducted in the past have demonstrated a prognostic benefit of CABG on survival. These findings were confirmed by the long-term follow-up of the STICH study in which, however, documentation of inducible ischaemia or myocardial viability was not predictive of a prognostic benefit of CABG. Revascularization via PCI in the recent REVIVED-BCIS2 study did not demonstrate a significant benefit in terms of death or heart failure hospitalization compared with optimal medical therapy. Pending the long-term follow-up of the REVIVED-BCIS2 study, optimized medical therapy, cardiac resynchronization therapy, and the implantable cardioverter defibrillator, where indicated, are the mainstay of treatment in patients with dilated ischaemic cardiomyopathy. The decision for coronary revascularization is made in the individual patient, possibly with a higher bias in patients with angina, three-vessel coronary artery disease, severe left ventricular dysfunction, and cardiac remodelling.

Myocardial Revascularization in Patients With Ischemic Cardiomyopathy: For Whom and How

Background Myocardial revascularization has been advocated to improve myocardial function and prognosis in ischemic cardiomyopathy (ICM). We discuss the evidence for revascularization in patients with ICM and the role of ischemia and viability detection in guiding treatment. Methods and Results We searched for randomized controlled trials evaluating the prognostic impact of revascularization in ICM and the value of viability imaging for patient management. Out of 1397 publications, 4 randomized controlled trials were included, enrolling 2480 patients. Three trials (HEART [Heart Failure Revascularisation Trial], STICH [Surgical Treatment for Ischemic Heart Failure], and REVIVED [REVascularization for Ischemic VEntricular Dysfunction]-BCIS2) randomized patients to revascularization or optimal medical therapy. HEART was stopped prematurely without showing any significant difference between treatment strategies. STICH showed a 16% lower mortality with bypass surgery compared with optimal medical therapy at a median follow-up of 9.8 years. However, neither the presence/extent of left ventricle viability nor ischemia interacted with treatment outcomes. REVIVED-BCIS2 showed no difference in the primary end point between percutaneous revascularization or optimal medical therapy. PARR-2 (Positron Emission Tomography and Recovery Following Revascularization) randomized patients to imaging-guided revascularization versus standard care, with neutral results overall. Information regarding the consistency of patient management with viability testing results was available in ≈65% of patients (n=1623). No difference in survival was revealed according to adherence or no adherence to viability imaging. Conclusions In ICM, the largest randomized controlled trial, STICH, suggests that surgical revascularization improves patients' prognosis at long-term follow-up, whereas evidence supports no benefit of percutaneous coronary intervention. Data from randomized controlled trials do not support myocardial ischemia or viability testing for treatment guidance. We propose an algorithm for the workup of patients with ICM considering clinical presentation, imaging results, and surgical risk.

Clinical Application of Myocardial Perfusion SPECT in Patients with Suspected or Known Coronary Artery Disease. What Role in the Multimodality Imaging Era?

Myocardial perfusion single photon emission computed tomography (SPECT) is widely used in assessing coronary artery disease (CAD) owing to its proven efficacy in extensive clinical experience. Like other functional tests, myocardial SPECT is recommended for the diagnosis of obstructive CAD, risk stratification assessment, and treatment decision making. Besides quantifying left ventricular volume, global and regional function by electrocardiography (ECG)-gated acquisition, myocardial SPECT can identify myocardial ischemia, scars, stunning, and viable hibernating myocardium. It provides comprehensive functional data across the spectrum of CAD and a cost-effective strategy in patients with intermediate pre-test probability of CAD or with a history of ischemic cardiomyopathy. With ongoing advances in cardiovascular prevention and risk factor management many patients referred for testing now have a low-to-intermediate probability of CAD. Besides, CAD has become a chronic condition resulting from novel therapeutic strategies. Against this background, approaches combining anatomical and functional tests in sequence or simultaneously include coronary artery calcium score integrated with perfusion imaging or fusion SPECT/coronary computed tomography angiography (CCTA). In this review we summarize current indications for myocardial perfusion SPECT and integration of SPECT with other imaging techniques to improve diagnostic performance, patient management, and outcome prediction in CAD.

Do Patients With Non-Viable Myocardium From Ischemic Cardiomyopathy Benefit From Revascularization? A Systematic Review And Meta-Analysis

BACKGROUND

Myocardial viability assessment is used to select patients who will derive the greatest benefit from revascularization. It remains controversial whether revascularization only benefits patients with ischemic cardiomyopathy who have viable myocardium. The objective of this meta-analysis was to compare mortality between patients with ischemic cardiomyopathy and non-viable myocardium who underwent revascularization and those who underwent medical therapy alone.

METHODS

The MEDLINE database was searched using PubMed to retrieve studies published up to December 2021. Inclusion criteria were 1. studies that evaluated the impact of revascularization (revascularization group) versus medical therapy alone (control group) following myocardial viability assessment; 2. patients who had coronary artery disease that was amenable to coronary artery bypass grafting or percutaneous coronary intervention; and 3. patients who had non-viable myocardium. The main outcome measure was all-cause mortality.

RESULTS

A total of 12 studies were included, evaluating 1363 patients with non-viable myocardium, of whom 501 patients underwent revascularization and 862 patients received medical therapy alone. There was a significant reduction in all-cause mortality (RR 0.76, 95 % CI: 0.62-0.93, I² = 0) in the revascularization group compared to the control group. There was no association between the type of viability imaging modality and the risk of all-cause mortality (P-interaction = 0.58).

CONCLUSIONS

The findings of this meta-analysis suggest a benefit from revascularization compared to medical therapy in patients with ischemic cardiomyopathy despite the lack of myocardial viability.

Identifying quality of life outcome patterns to inform treatment choices in ischemic cardiomyopathy

BACKGROUND

The Surgical Treatment for Ischemic Heart Failure (STICH) trial found that routine use of coronary artery bypass surgery (CABG) improved mean quality of life (QoL) scores relative to guideline-directed medical therapy (GDMT) in patients with ischemic cardiomyopathy. However, mean differences in QoL scores do not provide what patients want to know when facing a high-risk/high-benefit treatment choice.

METHODS

We analyzed Kansas City Cardiomyopathy Questionnaire (KCCQ) Overall Summary scores in CABG and GDMT patients over 36 months using a combination of statistical methods to group QoL data into clinically relevant outcome patterns (phenotype trajectories) and to then identify the main baseline predictors of each phenotype. QoL outcome phenotypes were developed using mixture models to define the dominant phenotype trajectories present in STICH QoL data. Logistic regression models were used to predict each patient's probability of achieving each outcome pattern with each treatment.

RESULTS

In STICH, 592 patients underwent CABG and 607 were managed with GDMT. Our analyses identified 3 phenotype trajectory patterns in both treatment groups. Two of the 3 trajectories showed improving patterns, and were classified as "good QoL trajectories," seen in 498 (84.1%) CABG and 449 (73.9%) GDMT patients. Defining a consequential CABG-GDMT treatment difference as a >10% higher absolute predicted probability of belonging to good QoL trajectories, 277 (23.5%) patients were more likely to have good outcome with CABG while 45 (3.8%) patients were more likely to have a good outcome with GDMT. For 644 (54.7%) patients, CABG and GDMT probabilities of a good outcome were within 5% of each other.

CONCLUSIONS

The pattern of QoL outcomes after CABG compared with GDMT in STICH followed 3 main phenotypic trajectories, which could be predicted based on individual baseline features. Patient-specific predictions about expected QoL outcomes with different treatment choices provide an intuitive framework for personalizing patient decision making.

Smaller left ventricular end-systolic diameter and lower ejection fraction at baseline associated with greater ejection fraction improvement after revascularization among patients with left ventricular dysfunction

Objectives

To investigate the predictive roles of pre-operative left ventricular (LV) size and ejection fraction (EF) in EF improvement and outcome following revascularization in patients with coronary artery disease (CAD) and LV dysfunction.

Background

Revascularization may improve EF and long-term outcomes of patients with LV dysfunction. However, the determinants of EF improvement have not yet been investigated comprehensively.

Materials and methods

Patients with EF measurements before and 3 months after revascularization were enrolled in a cohort study (No. ChiCTR2100044378). All patients had baseline EF ≤ 40%. EF improvement was defined as absolute increase in EF > 5%. According to LV end-systolic diameter (LVESD) (severely enlarged or not) and EF (≤35% or of 36–40%) at baseline, patients were categorized into four groups.

Results

A total of 939 patients were identified. A total of 549 (58.5%) had EF improved. Both LVESD [odds ratio (OR) per 1 mm decrease, 1.05; 95% CI, 1.04–1.07; P < 0.001] and EF (OR per 1% decrease, 1.06; 95% CI, 1.03–1.10; P < 0.001) at baseline were predictive of EF improvement after revascularization. Patients with LVESD not severely enlarged and EF ≤ 35% had higher odds of being in the EF improved group in comparison with other three groups both in unadjusted and adjusted analysis (all P < 0.001). The median follow-up time was 3.5 years. Patients with LVESD not severely enlarged and EF ≤ 35% had significantly lower risk of all-cause death in comparison with patients with LVESD severely enlarged and EF ≤ 35% [hazard ratio (HR), 2.73; 95% CI, 1.28–5.82; P = 0.009], and tended to have lower risk in comparison with patients with LVESD severely enlarged and EF of 36–40% (HR, 2.00; 95% CI, 0.93–4.27; P = 0.074).

Conclusion

Among CAD patients with reduced EF (≤ 40%) who underwent revascularization, smaller pre-operative LVESD and lower EF had greatest potential to have EF improvement and better outcome. Our findings imply the indication for revascularization in patients with LV dysfunction who presented with lower EF but smaller LV size.

Extent of Ejection Fraction Improvement After Revascularization Associated with Outcomes Among Patients with Ischemic Left Ventricular Dysfunction

Purpose

Ejection fraction (EF) has been reported to be a major predictor of improved survival in patients with heart failure. However, it is largely unknown whether the extent of improvement in EF affects the subsequent risk of mortality. This study sought to investigate change in EF after revascularization and the implication of these changes on clinical outcomes among patients with ischemic left ventricular dysfunction.

Patients and Methods

We conducted a cohort study (No. ChiCTR2100044378) of patients with reduced EF (≤40%) who received revascularization and had EF reassessment by echocardiography 3 months after revascularization. Patients were categorized according to the absolute change in EF: 1) EF worsened group (absolute decrease in EF >5%); 2) EF unchanged group (absolute change in EF −5% to 5%); 3) EF improved group (absolute increase in EF >5%).

Results

Of 974 patients, 84 (8.6%) had EF worsened, 317 (32.5%) had EF unchanged and 573 (58.8%) had EF improved. The median follow-up time was 3.5 years, during which 143 patients died. For each 5-unit increments in EF, the risk of death decreased by 20% (hazard ratio, HR, per 5% increases, 0.80; 95% CI, 0.73–0.86; P<0.001). Compared with EF improvement group, patients with EF worsened (HR, 3.35; 95% CI, 2.07–5.42; P<0.001) and patients with EF unchanged (HR, 2.05; 95% CI, 1.40–3.01; P<0.001) had significantly higher risk of all-cause death.

Conclusion

Changes in EF were inversely associated with the risk of mortality. The extent of EF improvement after revascularization might be a potential factor which defines clinical outcomes.

Impact of revascularization guided by functional testing in ischaemic cardiomyopathy

AIMS

The burden of ischaemia is a risk factor for adverse outcomes in ischaemic cardiomyopathy (ICM) but is not systematically tested when deciding on revascularization. Limited data exists in patients with ICM regarding the interaction between ischaemia and early coronary revascularization (ECR). This study sought to determine if the burden of ischaemia modifies the outcomes of ECR in ICM.

METHODS AND RESULTS

Consecutive patients with ICM (left ventricular ejection fraction < 40%) with a stress-rest gated single-photon emission computed tomography (N = 747) were followed-up for ECR and major cardiovascular events (MACEs, cardiovascular death, myocardial infarction, or heart failure hospitalization). A 1:1 matched population was selected using a propensity score for ECR. The interaction between ischaemia and ECR was evaluated in the matched cohort. In the initial cohort, 131 patients underwent ECR. Of them, 109 were matched to non-ECR patients. After a median follow up of 4.1 years, 102 (46.8%) patients experienced a MACE. The effect of revascularization on MACE was dependent of the percent of ischaemia (P for the interaction at 10% ischaemia = 0.021), so that a trend towards a decreased risk of MACE was seen in patients with >10% of ischaemia [hazard ratio (HR) = 0.59 (0.30-1.18)], whereas a non-significant increase of MACE was observed in those with <10% ischaemia (HR = 1.67 [0.94-2.96]).

CONCLUSIONS

In a contemporary cohort of patients with ICM, the beneficial effects of ECR may be mediated by the percent of ischaemia. This study supports stress testing in ICM and an ischaemia-guided approach for ECR.

Controversy: Critical Review of the Stich Trial and Assessment of Viability. “Back to the Future” Or Maybe Not

The management of patients with coronary artery disease and heart failure has been debated for years. In the 1980’s Braunwald coined the words “viability” and “stunning”. Multiple trials have been done since then. Since the early eighties coronary bypass grafting was considered as gold standard for patients with impaired left ventricular fraction and coronary artery disease. Since then, nuclear imaging studies have been used to evaluate the “viability” of the impaired areas and to decide if revascularisation would be reasonable. Beginning with the CASS study and ending with the more recent STICH study we aim to provide a “bird’s eye view” of the pros and cons for revascularisation. In addition, we aim to shed some light on the daily advancements in medical management, including devices and not just medication. We therefore chose the title “Back to the future” or maybe not.

Surgical Ventricular Restoration for Ischemic Heart Failure: A Glance at a Real-World Population

Surgical ventricular restoration (SVR) has repeatedly been suggested as a viable therapeutic strategy for ischemic heart failure (HF) patients, although the survival benefit is still debated. We investigated a real-world population treated with SVR in a single center with high case volumes. From July 2001 to June 2017, 648 patients (111 females) underwent SVR; coronary surgery was performed in 582 patients. Data were analyzed by dividing the population into two groups: Group I (371 patients operated between July 2001 and December 2007) and Group II (277 patients operated between January 2008 and June 2017). At baseline, Group I patients were more symptomatic for angina (47.4% versus 19.4%, p < 0.0001) and less symptomatic for HF (NYHA class III/IV, 46.3% versus 57%, p = 0.0071). The end-diastolic volume (106 mL/m2 versus 118.3 mL/m2, p < 0.0001) and the end-systolic volume (70.5 mL/m2 versus 81.5 mL/m2, p < 0.0001) were lower in Group I. The presence of 3-vessel coronary artery disease (CAD) was higher in Group I (73.3% versus 59.2%, p < 0.0001). Thirty-day mortality (6.64%) was similar in the two groups (p = 0.4475). The Kaplan−Meier estimate for all-cause mortality for the entire population was 13% at 2 years, 19.2% at 4 years and 36.6% at 8 years, and the probability was not different between groups (Log-rank = 0.11). In a real-world ischemic HF population, SVR may be carried out with favorable results; in patients with worse LV remodeling and less extensive CAD, SVR showed a trend toward a better outcome.

Cost-Effectiveness of Coronary Artery Bypass Surgery Versus Medicine in Ischemic Cardiomyopathy: The STICH Randomized Clinical Trial

BACKGROUND

The STICH Randomized Clinical Trial (Surgical Treatment for Ischemic Heart Failure) demonstrated that coronary artery bypass grafting (CABG) reduced all-cause mortality rates out to 10 years compared with medical therapy alone (MED) in patients with ischemic cardiomyopathy and reduced left ventricular function (ejection fraction ≤35%). We examined the economic implications of these results.

METHODS

We used a decision-analytic patient-level simulation model to estimate the lifetime costs and benefits of CABG and MED using patient-level resource use and clinical data collected in the STICH trial. Patient-level costs were calculated by applying externally derived US cost weights to resource use counts during trial follow-up. A 3% discount rate was applied to both future costs and benefits. The primary outcome was the incremental cost-effectiveness ratio assessed from the US health care sector perspective.

RESULTS

For the CABG arm, we estimated 6.53 quality-adjusted life-years (95% CI, 5.70-7.53) and a lifetime cost of $140 059 (95% CI, $106 401 to $180 992). For the MED arm, the corresponding estimates were 5.52 (95% CI, 5.06-6.09) quality-adjusted life-years and $74 894 lifetime cost (95% CI, $58 372 to $93 541). The incremental cost-effectiveness ratio for CABG compared with MED was $63 989 per quality-adjusted life-year gained. At a societal willingness-to-pay threshold of $100 000 per quality-adjusted life-year gained, CABG was found to be economically favorable compared with MED in 87% of microsimulations.

CONCLUSIONS

In the STICH trial, in patients with ischemic cardiomyopathy and reduced left ventricular function, CABG was economically attractive relative to MED at current benchmarks for value in the United States.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT00023595.

Diabetes Associated With Greater Ejection Fraction Improvement After Revascularization in Patients With Reduced Ejection Fraction

Objectives: To investigate the association between diabetes mellitus (DM) and ejection fraction (EF) improvement following revascularization in patients with coronary artery disease (CAD) and left ventricular (LV) dysfunction.

Background: Revascularization may improve outcomes of patients with LV dysfunction by improvement of EF. However, the determinants of EF improvement have not yet been investigated comprehensively.

Method: A cohort study (No. ChiCTR2100044378) of patient with repeated EF measurements after revascularization was performed. All patients had baseline EF ≤40%. Patients who had EF reassessment 3 months after revascularization were enrolled. Patients were categorized into EF unimproved (absolute increase in EF ≤5%) and improved group (absolute increase in EF >5%).

Results: A total of 974 patients were identified. 573 (58.8%) had EF improved. Patients with DM had greater odds of being in the improved group (odds ratio [OR], 1.42; 95% CI, 1.07–1.89; P = 0.014). 333 (34.2%) patients with DM had a greater extent of EF improvement after revascularization (10.5 ± 10.4 vs. 8.1 ± 11.2%; P = 0.002) compared with non-diabetic patients. The median follow-up time was 3.5 years. DM was associated with higher risk of overall mortality (hazard ratio [HR], 1.46; 95% CI, 1.02–2.08; P = 0.037). However, in EF improved group, the risk was similar between diabetic and non-diabetic patients (HR, 1.36; 95% CI, 0.80–2.32; P = 0.257).

Conclusions: Among patients with reduced EF, DM was associated with greater EF improvement after revascularization. Revascularization in diabetic patients might partially attenuate the impact of DM on adverse outcomes. Our findings imply the indication for revascularization in patients with LV dysfunction who present with DM.

Multivessel versus IRA-only PCI in patients with NSTEMI and severe left ventricular systolic dysfunction

Background

A substantial number of patients presenting with non-ST-elevation myocardial infarction (NSTEMI) and multivessel disease (MVD) have severe left ventricular systolic dysfunction (LVSD) (left ventricular ejection fraction (LVEF) less than 35%). But data are lacking regarding optimal percutaneous coronary intervention (PCI) strategy for these patients. The aim of this study was to compare the long-term outcomes of IRA (infarct-related artery)-only and multivessel PCI in patients with NSTEMI and MVD complicated by severe LVSD.

Methods

Among 13,104 patients enrolled in the PCI registry from November 2011 to December 2015, patients with NSTEMI and MVD with severe LVSD who underwent successful PCI were screened. The primary outcome was 3-year major adverse cardiovascular events (MACEs), defined as all-cause death, any myocardial infarction, stroke, and any revascularization.

Results

Overall, 228 patients were treated with IRA-only PCI (n = 104) or MV-PCI (n = 124). The MACE risk was significantly lower in the MV-PCI group than in the IRA-only PCI group (35.5% vs. 54.8%; hazard ratio [HR] 0.561; 95% confidence interval [CI] 0.378–0.832; p = 0.04). This result was mainly driven by a significantly lower risk of all-cause death (23.4% vs. 41.4%; hazard ratio [HR] 0.503; 95% confidence interval [CI] 0.314–0.806; p = 0.004). The results were consistent after multivariate regression, propensity-score matching, and inverse probability weighting to adjust for baseline differences.

Conclusions

Among patients with NSTEMI and MVD complicated with severe LVSD, multivessel PCI was associated with a significantly lower MACE risk. The findings may provide valuable information to physicians who are involved in decision-making for these patients.

Myocardial Viability Assessment Before Surgical Revascularization in Ischemic Cardiomyopathy: JACC Review Topic of the Week

Ischemic cardiomyopathy results from the combination of scar with fibrosis replacement and areas of dysfunctional but viable myocardium that may improve contractile function with revascularization. Observational studies reported that only patients with substantial amounts of myocardial viability had better outcomes following surgical revascularization. Accordingly, dedicated noninvasive techniques have evolved to quantify viable myocardium with the objective of selecting patients for this form of therapeutic intervention. However, prospective trials have not confirmed the interaction between myocardial viability and the treatment effect of revascularization. Furthermore, recent observations indicate that recovery of left ventricular function is not the principal mechanism by which surgical revascularization improves prognosis. In this paper, the authors describe a more contemporary application of viability testing that is founded on the alternative concept that the main goal of surgical revascularization is to prevent further damage by protecting the residual viable myocardium from subsequent acute coronary events.

Surgical revascularization in stable coronary artery disease with ventricular dysfunction: a single-center cohort study

PURPOSE

Stress-gated myocardial perfusion scintigraphy (MPS) is used for prognosis in stable coronary artery disease (CAD). We sought to assess coronary artery bypass grafting (CABG) outcomes in stable coronary artery disease patients who had myocardial perfusion scintigraphy and left ventricular (LV) dysfunction.

METHODS

Stable CAD patients who underwent CABG (2012-2019) and had stress-gated MPS were identified retrospectively. Based on the post-stress LV ejection fraction, a total of 130 patients were divided into a control group (51%) and LV dysfunction group (49%).

RESULTS

Patients with left ventricular dysfunction had significantly more mean summed stress score (22.1 ± 9 Vs. 12.5 ± 8; P ≤ 0.001) and summed resting score (14.6 ± 8 Vs. 3.7 ± 4; P ≤ 0.001) compared to the control group respectively. They also had a greater risk for developing low cardiac output syndrome after surgery (OR: 2.9, 95% CI 1.1-6.6, P=0.033). At 4.7 years, freedom from cardiac death was not statistically significant between the left ventricular dysfunction and control groups, respectively (90.2% vs. 95.6%; P=0.157). Cardiac death was not influenced by either ventricular dysfunction at the time of surgery (HR: 2.6, 95% CI 0.64-10.6, P=0.182) nor by having percent ischemic myocardium > 10% (HR: 0.86, 95% CI 0.23-3.24, P=0.826).

CONCLUSION

Significant myocardial ischemia and ventricular dysfunction before complete surgical revascularization did not influence the risk of cardiac-related deaths on long-term follow-up. This might be related to the improved survival after CABG in patients with myocardial ischemia and left ventricular dysfunction.

Coronary revascularisation in patients with ischaemic cardiomyopathy

Heart failure resulting from ischaemic heart disease is associated with a poor prognosis despite optimal medical treatment. Despite this, patients with ischaemic cardiomyopathy have been largely excluded from randomised trials of revascularisation in stable coronary artery disease. Revascularisation has multiple potential mechanisms of benefit, including the reversal of myocardial hibernation, suppression of ventricular arrhythmias and prevention of spontaneous myocardial infarction. Coronary artery bypass grafting is considered the first-line mode of revascularisation in these patients; however, evidence from the Surgical Treatment of Ischaemic Heart Failure (STICH) trial showed a reduction in mortality, though this only became apparent with extended follow-up due to an excess of early adverse events in the surgical arm. There is currently no randomised controlled trial evidence for percutaneous coronary intervention in patients with ischaemic cardiomyopathy; however, the REVIVED-BCIS2 trial has recently completed recruitment and will address this gap in the evidence. Future directions include (1) clinical trials of revascularisation in patients hospitalised with heart failure, (2) defining the role of viability and ischaemia testing in heart failure, (3) studies to enhance the understanding of the mechanistic effects of revascularisation and (4) generating models to refine pre- and post-revascularisation risk prediction.

Organ-saving surgical alternatives to treatment of heart failure

Over time, various surgical treatment strategies have evolved to manage advanced heart failure (HF). Scientific and technological breakthroughs through the last 50 years have put forward various surgical alternatives to patients with advanced HF encompassing surgical ventricular restoration to surgical gene therapy and stem cell replacement of the diseased ventricles. Organ-saving surgical options which used to be promising included dynamic cardiomyoplasty, partial resection of ventricle and cardiac wrapping with Acorn CorCap cardiac support device. These procedures were eventually abandoned due to negative outcomes and without proven disadvantages. Another organ-saving surgical option currently being considered but still make little sense is cardiac regeneration by stem cell therapy, i.e., cardiomyocyte restoration and replacement. Presently, the organ-saving surgical alternatives to treat end-stage HF are revascularization for ischemic cardiomyopathy, mitral valve surgery (repair or replacement) for ischemic mitral incompetence (IMI), left ventricular (LV) aneurysmectomy (surgical ventricular restoration) and mitral valve repair for IMI. These aforementioned procedures have become quite established approaches and with increasing experience are continuously being modified to improve outcome. Various mechanical circulatory support systems have emerged over time to improve functional status of patients with advanced HF, either as a bridge to heart transplantation or as a bridge to myocardial recovery. Likewise offered in those with contraindications to transplantation. Ventricular assist devices (VAD) can keep patients alive until an eventual transplantation. This article reviews the variety of the myriad of alternative organ-saving surgical alternatives that have been available or are currently available provided to patients with end-stage HF, their advantages and deficiencies, as well as prospects in HF therapy.

Conventional cardiac surgery in patients with end-stage coronary artery disease: yesterday and today

Surgical therapy of combined coronary artery disease (CAD) and heart failure, also referred to as end-stage CAD, has evolved throughout the years and patients are currently being offered traditional coronary artery bypass grafting (CABG), with or without surgical ventricle restoration (SVR), interventions for ischemic mitral valve regurgitation, heart transplantation or implantation of mechanical cardiovascular support systems. Among surgical methods, operative myocardial revascularization (with or without ventricle restoration) is still playing an important role, aiming at restoration of proper myocardial perfusion, especially if heart muscle viability is present. Facing the donor shortage, CABG may constitute a valuable alternative to transplantation in selected patients. In individuals considered not suitable for surgical revascularization, implantation of mechanical circulatory support (MCS) not only appears as a salvage procedure, but also allows for reevaluation of future therapy directions. This article aims at providing an overview of evolving and current surgical practices in patients with end-stage CAD.

Different left ventricular remodeling patterns and clinical outcomes between non-ischemic and ischemic etiologies in heart failure patients receiving sacubitril/valsartan treatment

AIMS

Although the beneficial effect of sacubitril/valsartan (SAC/VAL) compared to enalapril was consistent across ischaemic (ICM) and non-ischaemic cardiomyopathy (NICM) groups, the PARADIGM-HF study did not analyze the effect of ventricular remodelling on patients with different etiologies, which may affect clinical treatment outcomes. This study aimed to compare left ventricular ejection fraction (LVEF) following SAC/VAL treatment and its association with clinical outcomes.

METHODS AND RESULTS

A total of 1,576 patients were analyzed. Patients were grouped by LVEF changes following SAC/VAL treatment for 8-month period. LVEF improvement ≥15% was defined as "significant improvement", and <5% or worse was classified as "lack of improvement". The primary outcome was a composite of cardiovascular death and unplanned hospitalization for heart failure.Patients with NICM had lower baseline LVEF but improvement was significantly greater comparing to those with ICM (baseline 28.0 ± 7.7% vs. 30.1 ± 7.1%, p < 0.001, LVEF increase of 11.1 ± 12.6% vs. 6.7 ± 10.2%, p < 0.001). The effect of functional improvement of SAC/VAL on NICM patients showed bimodal distribution. Primary endpoints were inversely associated with LVEF changes in NICM patients: adjusted hazard ratio was 0.42 (95% confidence interval [CI] 0.31-0.58, p < 0.001) for NICM patients with significant improvement, and was 1.73 (95% CI 1.38-2.16, p < 0.001) for NICM patients but lack of improvement. Primary endpoints of ICM patients did not demonstrate an association with LVEF changes.

CONCLUSION

Patients with NICM had higher degree of LVEF improvement than those with ICM following SAC/VAL treatment, and significant improvement of LVEF in NICM patients indicates favorable outcome.

A review of the Surgical Treatment for Ischemic Heart Failure trial

Optimal treatment for patients with ischemic heart disease and severe left ventricular dysfunction is a debatable subject in the literature. The largest and only trial on the subject so far is the Surgical Treatment for Ischemic Heart Failure trial. This trial compared coronary artery bypass grafting with optimal medical treatment in one arm versus coronary artery bypass grafting with surgical ventricular restoration in the second arm. Recently, the 10-year follow-up data of various subsets of the trial have been published. This study reviews various pertinent clinical issues related to the trial and its sub-studies and their relevance in routine modern-day clinical practice.

Low left ventricular ejection fraction, complication rescue, and long-term survival after coronary artery bypass grafting

OBJECTIVES

To evaluate the association between low left ventricular ejection fraction (LVEF), complication rescue, and long-term survival after isolated coronary artery bypass grafting.

METHODS

National cohort study of patients who underwent isolated coronary artery bypass grafting (2000-2016) using Veterans Affairs Surgical Quality Improvement Program data. Left ventricular ejection fraction was categorized as ≥35% (n = 55,877), 25%-34% (n = 3893), or <25% (n = 1707). Patients were also categorized as having had no complications, 1 complication, or more than 1 complication. The association between LVEF, complication rescue, and risk of death was evaluated with multivariable Cox regression.

RESULTS

Among 61,477 patients, 6586 (10.7%) had a perioperative complication and 2056 (3.3%) had multiple complications. Relative to LVEF ≥35%, decreasing ejection fraction was associated with greater odds of complications (25%-34%, odds ratio, 1.30 [1.18-1.42]; <25%, odds ratio, 1.65 [1.43-1.92]). There was a dose-response relationship between decreasing LVEF and overall risk of death (≥35% [ref]; 25%-35%, hazard ratio, 1.46 [1.37-1.55]; <25%, hazard ratio, 1.68 [1.58-1.79]). Among patients who were rescued from complications, there were decreases in 10-year survival, regardless of LVEF. Among those rescued after multiple complications, LVEF was no longer associated with risk of death.

CONCLUSIONS

While decreasing LVEF is associated with post-coronary artery bypass grafting complications, patients rescued from complications have worse long-term survival, regardless of left ventricular function. Prevention and timely treatment of complications should remain a focus of quality improvement initiatives, and future work is needed to mitigate their long-term detrimental impact on survival.

Jeopardized Myocardium Defined by Late Gadolinium Enhancement Magnetic Resonance Imaging Predicts Survival in Patients With Ischemic Cardiomyopathy: Impact of Revascularization

Background The prognostic impact of jeopardized myocardium ( JM ) in patients with advanced ischemic cardiomyopathy ( ICM ) is unclear. We hypothesized that JM is an independent predictor of mortality in patients with advanced ICM . Methods and Results Patients with ICM who underwent cardiac magnetic resonance imaging between January 2002 and January 2013 were included in our study. JM was identified as a vascular territory with <50% myocardial scarring on cardiac magnetic resonance imaging and with >70% stenosis in a major coronary vessel that was not subsequently revascularized. A propensity score was developed for revascularization. A multivariable Cox proportional hazards model was used to evaluate the association of JM with all-cause mortality. We evaluated 631 patients over a mean follow-up of 5.1 years. Overall, 336 patients underwent subsequent revascularization during the follow-up period, among whom 23% had remaining JM , while 295 patients were medically treated (57% with JM ). There were 204 deaths (32%). On multivariable analysis, JM (hazard ratio, 1.88; 95% confidence interval, 1.38-2.55 [ P<0.001]) was independently associated with all-cause mortality after adjusting for multiple other factors. The risk associated with the presence of JM increased by 5% for every 10-unit increase in left ventricular end-systolic volume index. Conclusions JM is an independent and incremental predictor of mortality in patients with advanced ICM . Patients undergoing revascularization with residual JM had similar risk of mortality compared with medically treated patients with JM . The risk associated with JM significantly increased in the presence of worsening adverse left ventricular remodeling. Cardiac magnetic resonance viability assessment may provide important risk stratification in patients with ICM .

Percutaneous coronary intervention outcomes in patients with stable coronary disease and left ventricular systolic dysfunction

AIMS

We sought to better understand the role of percutaneous coronary intervention (PCI) in patients with stable coronary artery disease (CAD) and moderate or severe left ventricular systolic dysfunction.

METHODS AND RESULTS

Using data from the Duke Databank for Cardiovascular Disease, we analysed patients who underwent coronary angiography at Duke University Medical Center (1995-2012) that had stable CAD amenable to PCI and left ventricular ejection fraction ≤35%. Patients with acute coronary syndrome or Canadian Cardiovascular Society class III or IV angina were excluded. We used propensity-matched Cox proportional hazards to evaluate the association of PCI with mortality and hospitalizations. Of 901 patients, 259 were treated with PCI and 642 with medical therapy. PCI propensity scores created from 24 variables were used to assemble a matched cohort of 444 patients (222 pairs) receiving PCI or medical therapy alone. Over a median follow-up of 7 years, 128 (58%) PCI and 125 (56%) medical therapy alone patients died [hazard ratio 0.87 (95% confidence interval 0.68, 1.10)]; there was also no difference in the rate of a composite endpoint of all-cause mortality or cardiovascular hospitalization [hazard ratio 1.18 (95% confidence interval 0.96, 1.44)] between the two groups.

CONCLUSIONS

In this well-profiled, propensity-matched cohort of patients with stable CAD amenable to PCI and moderate or severe left ventricular systolic dysfunction, the addition of PCI to medical therapy did not improve long-term mortality, or the composite of mortality or cardiovascular hospitalization. The impact of PCI on other outcomes in these high-risk patients requires further study.

Myocardial Viability and Long-Term Outcomes in Ischemic Cardiomyopathy

BACKGROUND

The role of assessment of myocardial viability in identifying patients with ischemic cardiomyopathy who might benefit from surgical revascularization remains controversial. Furthermore, although improvement in left ventricular function is one of the goals of revascularization, its relationship to subsequent outcomes is unclear.

METHODS

Among 601 patients who had coronary artery disease that was amenable to coronary-artery bypass grafting (CABG) and who had a left ventricular ejection fraction of 35% or lower, we prospectively assessed myocardial viability using single-photon-emission computed tomography, dobutamine echocardiography, or both. Patients were randomly assigned to undergo CABG and receive medical therapy or to receive medical therapy alone. Left ventricular ejection fraction was measured at baseline and after 4 months of follow-up in 318 patients. The primary end point was death from any cause. The median duration of follow-up was 10.4 years.

RESULTS

CABG plus medical therapy was associated with a lower incidence of death from any cause than medical therapy alone (182 deaths among 298 patients in the CABG group vs. 209 deaths among 303 patients in the medical-therapy group; adjusted hazard ratio, 0.73; 95% confidence interval, 0.60 to 0.90). However, no significant interaction was observed between the presence or absence of myocardial viability and the beneficial effect of CABG plus medical therapy over medical therapy alone (P = 0.34 for interaction). An increase in left ventricular ejection fraction was observed only among patients with myocardial viability, irrespective of treatment assignment. There was no association between changes in left ventricular ejection fraction and subsequent death.

CONCLUSIONS

The findings of this study do not support the concept that myocardial viability is associated with a long-term benefit of CABG in patients with ischemic cardiomyopathy. The presence of viable myocardium was associated with improvement in left ventricular systolic function, irrespective of treatment, but such improvement was not related to long-term survival. (Funded by the National Institutes of Health; STICH ClinicalTrials.gov number, NCT00023595.).

Burden of medical co-morbidities and benefit from surgical revascularization in patients with ischaemic cardiomyopathy

AIMS

The landmark STICH trial found that surgical revascularization compared to medical therapy alone improved survival in patients with heart failure (HF) of ischaemic aetiology and an ejection fraction (EF) ≤ 35%. However, the interaction between the burden of medical co-morbidities and the benefit from surgical revascularization has not been previously described in patients with ischaemic cardiomyopathy.

METHODS AND RESULTS

The STICH trial (ClinicalTrials.gov Identifier: NCT00023595) enrolled patients ≥ 18 years of age with coronary artery disease amenable to coronary artery bypass grafting (CABG) and an EF ≤ 35%. Eligible participants were randomly assigned 1:1 to receive medical therapy (MED) (n = 602) or MED/CABG (n = 610). A modified Charlson co-morbidity index (CCI) based on the availability of data and study definitions was calculated by summing the weighted points for all co-morbid conditions. Patients were divided into mild/moderate (CCI 1-4) and severe (CCI ≥ 5) co-morbidity. Cox proportional hazards models were used to evaluate the association between CCI and outcomes and the interaction between severity of co-morbidity and treatment effect. The study population included 349 patients (29%) with a mild/moderate CCI score and 863 patients (71%) with a severe CCI score. Patients with a severe CCI score had greater functional limitations based on 6-min walk test and impairments in health-related quality of life as assessed by the Kansas City Cardiomyopathy Questionnaire. A total of 161 patients (Kaplan-Meier rate = 50%) with a mild/moderate CCI score and 579 patients (Kaplan-Meier rate = 69%) with a severe CCI score died over a median follow-up of 9.8 years. After adjusting for baseline confounders, patients with a severe CCI score were at higher risk for all-cause mortality (hazard ratio 1.44, 95% confidence interval 1.19-1.74; P < 0.001). There was no interaction between CCI score and treatment effect on survival (P = 0.756).

CONCLUSIONS

More than 70% of patients had a severe burden of medical co-morbidities at baseline, which was independently associated with increased risk of death. There was not a differential benefit of surgical revascularization with respect to survival based on severity of co-morbidity.

CABG in patients with left ventricular dysfunction: indications, techniques and outcomes

Ischemic chronic heart failure (CHF) represents one of the cardiovascular diseases with the worst degree of morbidity and mortality in the western world, and with the highest health care costs. Despite several studies demonstrated that surgical revascularization (CABG), especially in the presence of viable myocardium, improve heart function, and therefore, survival, the matter remains unclear and controversial. In the late 1970s, the Coronary Artery Surgery Study showed that a subgroup of patients with coronary artery disease, angina, and reduce LV function had a significant survival benefit after CABG compared to those treated medically. The key concept behind this observation was the presence of viable myocardium, which can resume function following revascularization. In contrary, the surgical treatment for ischemic heart failure (STICH) trial, which randomized patients with CAD and LV dysfunction to evidence-based medical therapy or CABG plus medical therapy, failed to demonstrate at a median follow-up of 56 months a significant difference between the CABG group and the medical therapy group in the rate of death from any cause. However, the results of the STICH extension study (STICHES) at 10 years follow-up demonstrated that CABG is associated with a significant reduction in all-cause mortality, cardiovascular mortality, and readmission for heart compared to optimal medical therapy (OMT) in patients with severe ischemic LV dysfunction. Therefore, this review discusses the available evidences in literature, from observational studies to randomized trials, including operative techniques and controversial issues, in order to better clarify the role of CABG in the current management of ischemic patients with LVD.

The radial artery in coronary surgery, 2018

It is now 25 years since the radial artery (RA) was reintroduced in coronary surgery. It has evolved into being a significant coronary artery bypass conduit and ranks third in usage after the internal thoracic artery (ITA) and saphenous vein grafts (SVG). Its advantages are that it can be readily and efficiently harvested, is of good length and appropriate size for coronary artery bypass graft (CABG) surgery, is robust and easy to handle, and remains free of atheroma, and there is minimal wound morbidity. The RA must be used judiciously with attention to spasm prophylaxis because of its muscular wall, and by avoiding competitive flow. Its patency is equivalent to the ITAs when placed to similar coronary territories and under similar conditions (stenosis, size, quality) and RA patencies are always superior to those of SVG in both observational and randomized studies-88-90% versus 50-60% at 10 years, and 80-87% versus 25-40% at 20 years. Its use and excellent patencies result in survival results equivalent to bilateral internal thoracic artery (BITA) grafting and always superior to left internal thoracic artery (LITA) +SVG. Typical radial artery multiarterial bypass grafting (RA-MABG) 10-year survivals are 80-90% versus 70-80% for LITA-SVG. In general, for every 100 patients undergoing CABG, 10 more patients will be alive at 10 years post-operatively. The RA also is important in achieving total arterial revascularization, and several reports indicate a further survival advantage for patients having three arterial grafts over two. The RAs are especially useful in diabetic, morbidly obese patients, those with conduit shortage, and leg pathology, and in coronary reoperations. Although the RA has equivalent patencies to the right internal thoracic artery (RITA), it is much more versatile. RAs that have been instrumented by angiography or percutaneous coronary intervention should be avoided. The radial artery has proved to be an excellent arterial conduit, is equivalent to but more versatile than the RITA, and is always superior to SVG. Its use should be part of every coronary surgeon's skill set.

Development of a multivariate model to predict significant coronary artery disease in Thai patients with left ventricular systolic dysfunction and determine the applicability of coronary angiography: a single-center, retrospective, case–control study

Background

Coronary angiography (CAG) or stress imaging has been performed in almost all Thai patients with left ventricular (LV) systolic dysfunction. If CAG results reveal insignificant coronary stenosis, such patients are diagnosed with nonischemic cardiomyopathy (NICM); however, CAG is considered to provide no benefit and may even harm these patients because it is invasive.

Objectives

To identify predictors associated with significant coronary artery disease (CAD) (stenosis) in Thai patients with LV systolic dysfunction without angina and without LV regional wall motion abnormality and create a prediction score.

Method

Retrospective data from patients at a single tertiary-care center with LV systolic dysfunction (LV ejection fraction <50%) diagnosed between August 2000 and October 2014 were separated into a group with ischemic cardiomyopathy (ICM) and a group with NICM according to CAG. Predictors associated with CAD found in normal populations were determined. Multivariate analysis was used to identify predictors associated with significant coronary stenosis in patients with LV systolic dysfunction to develop a model to create a prediction score.

Results

We included data registered from 240 Thai patients with LV systolic dysfunction. Predictors associated with ICM were age (>60 years), sex (male), and a history of diabetes mellitus (DM). Predictors associated with NICM were body mass index (BMI) >25 kg/m2 and the presence of left bundle branch block (LBBB) on electrocardiography. A simplified equation to predict significant CAD in patients with LV systolic dysfunction is: 3(male sex) + 3(age >60 y) – 5(BMI >25 kg/m2) - 5(LBBB) + 5(DM) - 5. The sensitivity and specificity of this score are 60.5% and 85.1%, respectively.

Conclusion

Our prediction score has modest sensitivity, but high specificity for predicting significant CAD and can be used to determine who should not undergo CAG.